No step buzzer

[Take2]

The other day I left open the Hab door during a downpour. Since then the Habs step alarm no longer sounds.
It’s a Thule motorised step on a 2020 Ducato. The switch in the step checked out ok on the DVM
Any help greatly appreciated

 

[Eddystone]

The other day I left open the Hab door during a downpour. Since then the Habs step alarm no longer sounds.
It’s a Thule motorised step on a 2020 Ducato. The switch in the step checked out ok on the DVM
Any help greatly appreciated

The first thing to check is the fuse.

 

[Take2]

The first thing to check is the fuse.

My thought too. I’ve found the buzzer beneath passenger seat but can’t locate the fuse. I’ll remove the seat panels tomorrow for a better look. Thanks

 

[Tombola]

Poss behind drivers seat in floor base of door pillar

 

[BobilG600]

I’d agree with checking the fuse first. On our motorhome it is on a small individual circuit board that has two fuses and a relay mounted next to the electrobloc. I’m wondering if this circuit board is part of the kit supplied with the step as it is totally self contained. I don’t know where you will fold yours but it won’t necessarily be near the buzzer.

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[BobilG600]

This is the step control circuit board on our motorhome. The buzzer is in the cab but is wired to this board which is right at the back with all the 12v bits. Have you got anything like this you can see on your motorhome? If so, check the fuses (2A and 20A).

 

[Take2]

So you’re saying this circuit for the step is situated under the passenger seat by the Elektriblock thingy?

 

[raysalaugh]

When is your alarm supposed to sound?, mine only triggers if I start the engine with step out.

 

[Speve]

I would have thought if the step works the fuse is ok the buzzer would not be fused separately surley?

 

[HugoBNB]

When is your alarm supposed to sound?, mine only triggers if I start the engine with step out.

Ours was like that, but only if we had the habitation power on. Otherwise, it didn't buzz and retract when we started the engine.

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[Orion]

I would have thought if the step works the fuse is ok the buzzer would not be fused separately surley?

That’s how it ‘s meant to work I believe, only the one 20A fuse on the main power supply to the step. No buzzer or warning light on ours but I wired it in with the relay for automatic retraction by following the Thule instructions:

To the OP is the buzzer circuit being made through the grey wire from the step switch?

 

[Take2]

When is your alarm supposed to sound?, mine only triggers if I start the engine with step out.

 

[Take2]

Tested that but not buzzer sound with engine in and step out

 

[Take2]

That’s how it ‘s meant to work I believe, only the one 20A fuse on the main power supply to the step. No buzzer or warning light on ours but I wired it in with the relay for automatic retraction by following the Thule instructions:
View attachment 826645
View attachment 826647

To the OP is the buzzer circuit being made through the grey wire from the step switch?

Thanks for all the info. Mines not automatic
Not quite sure what you’re asking regarding the grey wire? The switch that is activated by the step position works. It’s open cct when step out else short cct when step in

 

[Orion]

Thanks for all the info. Mines not automatic
Not quite sure what you’re asking regarding the grey wire? The switch that is activated by the step position works. It’s open cct when step out else short cct when step in

Shouldn’t that be the other way round? NC with step out to make the circuit for the warning buzzer to sound when the ignition ‘on’ supplies the other side of the buzzer with the 12v feed?

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[suavecarve]

When ours did something similar the relay was under the van by the step.

When you said loads of rain, makes me wonder if after a few years it finally got damp and needs a new circuit board like ours did, especially if you have gone through some big puddles.

I reckon it was 10 years ago and £100 from the powers that be, or find a Post Graduate in electronic engineering and offer him 5 litres of cheap wine. (No prizes for guessing what I did). Finding it and putting some rice on to it in the first instance (if i am right about the rain seeping in) would be my first port of call.

Best of luck

 

[Take2]

Shouldn’t that be the other way round? NC with step out to make the circuit for the warning buzzer to sound when the ignition ‘on’ supplies the other side of the buzzer with the 12v feed?

Now you’ve said that my idea does sound counter intuitive. But thinking back all those four days ago I may have miss recalled what happened. As I said, the problem seemed to start after we’d left the Hab door open during a down pour which allowed a switch mounted on the hinge side of the door to get wet. Think it’s this that is OC WHEN FOR OPEN. I’LL DOUBLE CHECK THAT and get back

 

[Take2]

When ours did something similar the relay was under the van by the step.

When you said loads of rain, makes me wonder if after a few years it finally got damp and needs a new circuit board like ours did, especially if you have gone through some big puddles.

I reckon it was 10 years ago and £100 from the powers that be, or find a Post Graduate in electronic engineering and offer him 5 litres of cheap wine. (No prizes for guessing what I did). Finding it and putting some rice on to it in the first instance (if i am right about the rain seeping in) would be my first port of call.

Best of luc

 

[Orion]

……. the problem seemed to start after we’d left the Hab door open during a down pour which allowed a switch mounted on the hinge side of the door to get wet. Think it’s this that is OC WHEN FOR OPEN. I’LL DOUBLE CHECK THAT and get back

That sort or makes more sense, although when not being pressed for the ‘in’ and ‘out’ operating positions it should effectively be open circuit.

As you can see from the wiring diagram the switch that operates the warning buzzer/light circuit is separate from the step motor switching, and provides the -ve path to the buzzer when the step is extended via the grey wire. I’d check for that switch being stuck OC, continuity on the grey wire between the switch and buzzer, and put the buzzer to -ve temporarily with a patch lead while livening up the ignition feed to it. That should help narrow down where the problem lies.

 

[Take2]

Here’s said switch on Hab door which is open cct when door open. Not sure what this sw is

for but perhaps mistakenly, thought it had something to do with step issue as it got wet while door left open when step failed

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[Take2]

That sort or makes more sense, although when not being pressed for the ‘in’ and ‘out’ operating positions it should effectively be open circuit.

As you can see from the wiring diagram the switch that operates the warning buzzer/light circuit is separate from the step motor switching, and provides the -ve path to the buzzer when the step is extended via the grey wire. I’d check for that switch being stuck OC, continuity on the grey wire between the switch and buzzer, and put the buzzer to -ve temporarily with a patch lead while livening up the ignition feed to it. That should help narrow down where the problem lies.

Also here is what I thought was the buzzer under passenger seat by the Bloc thingy

 

[Take2]

That sort or makes more sense, although when not being pressed for the ‘in’ and ‘out’ operating positions it should effectively be open circuit.

As you can see from the wiring diagram the switch that operates the warning buzzer/light circuit is separate from the step motor switching, and provides the -ve path to the buzzer when the step is extended via the grey wire. I’d check for that switch being stuck OC, continuity on the grey wire between the switch and buzzer, and put the buzzer to -ve temporarily with a patch lead while livening up the ignition feed to it. That should help narrow down where the problem lies.

I’ll double check which way round step sw works after lunch. One thing I forgot to mention about the buzzer was that with ignition on there’s12v across it with ignition on and step in or out??

 

[Orion]

Curiouser, and curiouser!

Deffo looks like a warning buzzer under the seat, have you tried putting a -ve to it when the ignition is on? If it then sounds you can head further on towards the switching side to find where the -ve path is being interrupted.

EDIT to add. Try continuity between that door switch and -ve on the vehicle and also switch to -ve on the buzzer. If the installation was made by someone who didn’t get their head around the Thule wiring then I suppose there’s always a chance they’ve either rigged up a totally independent buzzer circuit or integrated it with an additional ‘hab door open’ warning?

 

[Take2]

Curiouser, and curiouser!

Deffo looks like a warning buzzer under the seat, have you tried putting a -ve to it when the ignition is on? If it then sounds you can head further on towards the switching side to find where the -ve path is being interrupted.

EDIT to add. Try continuity between that door switch and -ve on the vehicle and also switch to -ve on the buzzer. If the installation was made by someone who didn’t get their head around the Thule wiring then I suppose there’s always a chance they’ve either rigged up a totally independent buzzer circuit or integrated it with an additional ‘hab door open’ warning?

I’ve just come in to post latest findings. And sounds like you’re correct. I more realise the the buzzer actually getting two switched inputs. 12v from ignition sw and negative from steps positional sw. I checked continuity of the buzzer negative with step in/out and am getting continuity and OC respectively. Proving the buzzer must have failed. Next stop, Amazon. Thanks, I’ll try an remember to post if new buzzer fixed it

 

[Orion]

Be interesting to see if the integral step switch is actually connected to the buzzer circuit correctly (grey wire -ve) and if the extra door switch is just there to warn about leaving the hab door open? Maybe take that one out of circuit to test it?

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[Take2]

Be interesting to see if the integral step switch is actually connected to the buzzer circuit correctly (grey wire -ve) and if the extra door switch is just there to warn about leaving the hab door open? Maybe take that one out of circuit to test it?

Buzzer fitted and alarm not functioning as it should but still non the wiser about the Hab door sw. I’ll ask at its Hab service in December

 

[FrankNicklin]

My Swift does buzz and auto close the step as soon as I start the ignition.

The white switch in the picture is set way back from the HAB door so is there a plate on the door to activate this switch when the door is closed.

 

[Orion]

Buzzer fitted and alarm not functioning as it should but still non the wiser about the Hab door sw. I’ll ask at its Hab service in December

I’m at a loss to understand the purpose of that switch as the circuit for warning buzzer/light and its activating switch are integral with the step - the grey wire. If there’s any reason to dig into your wiring further it might be a good time to investigate fitting the auto retraction relay and condenser as the rest of the wiring must already be in place somewhere.

 

[Take2]

Buzzer fitted and alarm not functioning as it should but still non the wiser about the Hab door sw. I’ll ask at its Hab service in December

Whoops!!!
Buzzer fitted and alarm NOW functioning as it should but still non the wiser about the Hab door sw. I’ll ask at its Hab service in December